do i need to cycle?

(I hope I put this in the right place)




I am setting up a new 2 gallon tank, sand and rock is dead, except for the rock I will seed it with, 1 gallon will be new water the other 1 gallon will be out of a older tank. Will I need to cycle my new tank?

 

You should be pretty good. I did that with my 14 gallon. I took water out of my 55 gallon and then put in about 50% new water in. In the same day I put my small dwarf angel and my two spot blenny in. They both lasted quite a while. The angel ended up dying because of my rocks falling over.

I would say that you are fine. good luck

 

I would always assume at least a small cycle will take place, even "dead" rock can have organics on/in it that will begin to decompose in a new tank so I would wait. Don't rush anything, get your test kits fired up and make sure!

 

Thinks.
I will try to post some pics later

 

Big YES. You do need to cycle. First of all, in a 2 gallon tank bad chemicals like ammonia and nitrites can build up very quickly (since they don't have a lot of water to dilute them). So you definitely want to be sure that you have enough helpful bacteria to clear those compounds. And because most of your rock is not live and cured, it will not have much helpful bacteria to convert ammonia to nitrates. The water you add from an established tank has very few helpful bacteria in it, since these live on substrate and rock, not in the water column.

So to answer your question, please be careful, go slow, and cycle your tank.

 

Agreed! Also, you may want to add a cpl cups of the established tanks substrate to seed as well. Good luck. FYI, I just started a 5g. When I did my last water change, I used the old water from our 37g and filled up the 5g. I also added maybe 2 cups of crushed coral from the 37 and also took 2 pcs of lr and added it. I still had a mini cycle that lasted approx 5-7 days.

 

I am going to add one rock from my old tank to the new one, but I didn’t think about adding substrate from the old tank.

Hear are some pics (water is cloudy from the sand)

 

There really is very little benefit if any to using used tank water. the beneficial bacteria are not free swimming but live in the rock and substrate. I would start with all new water myself. You will go though a cycle regardless, by seeding it with live rock and possibly some sand it may be quicker but its still going to happen.

 

I agree with this, it's not the water that is beneficial, but the rock or substrate. I'm sure the water contains some bacteria, but not in the concentrations that you need.

 

using water from the old tank may decrease die off on the live rock, due to all the parameters being exactly the same.